DHCP is disabled in the webserver, yes... has been set to a static ip 192.168.1.200
DHCP in router is running in the range 192.168.1.2 - 192.168.1.99. And I made a static IP setup and portforwarding to the server ip 192.168.1.200

You got me thinking about the setup from the start! And therefore I clown'ed around a little more and found this:

http://www.howtoforge.com/forums/showthread.php?t=41201[...]
ISPConfig 3 is not changing anything in /etc/network/interfaces by default as the network management feature is disabled in a config file. You must have anabled this manually in the ispconfig config.inc.php file and there you can disable the network configuration again.
[...]

And I did enable that function, due to the text regarding:"The network configuration option is only available for Debian and Ubuntu Servers. Do not enable this option if your network interface is not eth0. etc..."

So thanks for that )

But in the same section "Server Config - Nameservers" these ip's is shown:Nameservers: 8.8.8.8,8.8.4.4

..and this after reading 232 additional sites www.howtoforge.com/forums/archive/index.php/t-53063.html[...]
// If your ISP provided one or more IP addresses for stable
// nameservers, you probably want to use them as forwarders.
// Uncomment the following block, and insert the addresses replacing
// the all-0's placeholder.

forwarders {
8.8.8.8;8.8.4.4;
};
[...]

So are these ip's ok? I have a nameserver myself and uses a secondary some other place. Do I replace "8.8.8.8;8.8.4.4" with my own? Or what is usually done?